In recent years, flat panel displays are used in various commodity products and fields, and thus flat panel displays are required to have a large size, high image quality and low power consumption.
Under the circumstances, organic EL display devices, which include an organic EL (electroluminescent) element that utilizes electro luminescence of an organic material, are attracting great attention as all-solid state flat panel displays that are excellent as having capability of low voltage operation, quick responsivity and light emission.
In an active matrix type organic EL display device, e.g., a thin-film organic EL element is provided on a substrate having TFTs (thin-film transistors). The organic EL element includes an organic EL layer (including a light emitting layer) that is disposed between a pair of electrodes. The TFTs are connected to one of the pair of electrodes. A voltage is applied across the pair of electrodes so that the light emitting layer emits light, thereby displaying images.
In the above conventional organic EL display device, it is known that a sealing film is formed on the organic EL element in order to prevent the degradation of the organic EL element due to moisture or oxygen.
In the above conventional organic EL display device, as described in Patent Document 1 below for example, a sealing film composed of a resin sealing film (an organic layer) and an inorganic passivation sealing film (an inorganic layer) that are stacked alternately is formed on the organic EL element. It has been considered that in the conventional organic EL display device, the sealing film can prevent the degradation of the organic EL element due to moisture or oxygen.